[compiler-rt] r313091 - Determine up front which projects are enabled.

[Zachary Turner via llvm-commits]

Author: zturner
Date: Tue Sep 12 16:32:34 2017
New Revision: 313091

URL: http://llvm.org/viewvc/llvm-project?rev=313091&view=rev
Log:
Determine up front which projects are enabled.

Some projects need to add conditional dependencies on other projects.
compiler-rt is already doing this, and I attempted to add this to
debuginfo-tests when I ran into the ordering problem, that you can't
conditionally add a dependency unless that dependency's CMakeLists.txt
has already been run (which would allow you to say if (TARGET foo).

The solution to this seems to be to determine very early on the entire
set of projects which is enabled. This is complicated by the fact that
there are multiple ways to enable projects, and different tree layouts
(e.g. mono-repo, out of -tree, external, etc). This patch attempts to
centralize all of this into one place, and then updates compiler-rt to
demonstrate as a proof of concept how this can simplify code.

Differential Revision: https://reviews.llvm.org/D37637

Modified:
    compiler-rt/trunk/CMakeLists.txt

Modified: compiler-rt/trunk/CMakeLists.txt
URL: http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/CMakeLists.txt?rev=313091&r1=313090&r2=313091&view=diff
==============================================================================
--- compiler-rt/trunk/CMakeLists.txt (original)
+++ compiler-rt/trunk/CMakeLists.txt Tue Sep 12 16:32:34 2017
@@ -225,7 +225,7 @@ append_list_if(COMPILER_RT_DEBUG -DSANIT
 # always respect the optimization flags set by CMAKE_BUILD_TYPE instead.
 if (NOT MSVC)
 
-  # Build with optimization, unless we're in debug mode. 
+  # Build with optimization, unless we're in debug mode.
   if(COMPILER_RT_DEBUG)
     list(APPEND SANITIZER_COMMON_CFLAGS -O0)
   else()
@@ -315,28 +315,16 @@ endif()
 
 add_subdirectory(include)
 
-set(COMPILER_RT_LIBCXX_PATH ${LLVM_MAIN_SRC_DIR}/projects/libcxx)
-if(EXISTS ${COMPILER_RT_LIBCXX_PATH}/)
-  set(COMPILER_RT_HAS_LIBCXX_SOURCES TRUE)
-else()
-  set(COMPILER_RT_LIBCXX_PATH ${LLVM_MAIN_SRC_DIR}/../libcxx)
-  if(EXISTS ${COMPILER_RT_LIBCXX_PATH}/)
-    set(COMPILER_RT_HAS_LIBCXX_SOURCES TRUE)
-  else()
-    set(COMPILER_RT_HAS_LIBCXX_SOURCES FALSE)
-  endif()
+set(COMPILER_RT_HAS_LIBCXX_SOURCES ${LLVM_PROJECT_LIBCXX_ENABLED})
+if (LLVM_PROJECT_LIBCXX_ENABLED)
+  set(COMPILER_RT_LIBCXX_PATH ${LLVM_PROJECT_LIBCXX_SOURCE_DIR})
+  message("compiler-rt libcxx enabled at ${COMPILER_RT_LIBCXX_PATH}")
 endif()
 
-set(COMPILER_RT_LLD_PATH ${LLVM_MAIN_SRC_DIR}/tools/lld)
-if(EXISTS ${COMPILER_RT_LLD_PATH}/ AND LLVM_TOOL_LLD_BUILD)
-  set(COMPILER_RT_HAS_LLD TRUE)
-else()
-  set(COMPILER_RT_LLD_PATH ${LLVM_MAIN_SRC_DIR}/../lld)
-  if(EXISTS ${COMPILER_RT_LLD_PATH}/ AND LLVM_TOOL_LLD_BUILD)
-    set(COMPILER_RT_HAS_LLD TRUE)
-  else()
-    set(COMPILER_RT_HAS_LLD FALSE)
-  endif()
+set(COMPILER_RT_HAS_LLD ${LLVM_PROJECT_LLD_ENABLED})
+if (LLVM_PROJECT_LLD_ENABLED)
+  set(COMPILER_RT_LLD_PATH ${LLVM_PROJECT_LLD_SOURCE_DIR})
+  message("compiler-rt lld enabled at ${COMPILER_RT_LLD_PATH}")
 endif()
 pythonize_bool(COMPILER_RT_HAS_LLD)